I was going to post this a long time ago, and shot a demonstration video, but never posted.
My Brymen BM037 has a strange bug: in Crest mode, which is made to measure momentary max and min values (within a few ms window IIRC), it shows readings ~4-5 times higher than the actual value is. Normal continuous measurements work fine. It's not a user error: there's no unaccounted for inrush current, it can be seen with plain DC constant current.
Now, the meter shown in the video has this bug in both the 60 A and 600 A ranges. I did communicate with the distributor and they did their best to resolve this. They even contacted Brymen I believe, but it resulted in pretty much nothing. They proposed me to return the meter and refund the money, but I didn't want the money, I wanted a nice clamp meter with good peak current registration.
I don't remember precisely what happened then, but I believe they exchanged the original unit (shown in the video) with another, and the one that I currently own has this bug only in the 60 A range. The 600 A range works fine, and Crest measurements aren't different from normal ones when measuring a stable DC current. I think that was where I considered the issue settled: resolution in the 600 A range is sufficient, as I don't usually need precise measurements of inrush current, and for anything precise and/or low-current I'd need to use a dedicated shunt or Hall sensor connected to an oscilloscope anyway.
Does anyone else have this bug? If not, what's your firmware version (hold the Hold button during power-on)? Mine shows "030d".
Any idea if it can be fixed?
Here's the video showing the issue with the old unit that had it in both ranges. Unfortunately I didn't record what its firmware version was.